I have a light weight pond boat and a small pontoon boat. I use a size 27 battery and at the end of most days it reads 60-70% still left, according to my battery meter. I am thinking of trying a size 22 AGM battery because of the lighter weight. My question is will the 22 series be addiquit?

Most likely not.

 

What is the weight difference?

 

The deeper you discharge a battery the sooner you'll have to replace it. Rather than looking at a battery tester you should look at a voltmeter and when you drop below 12.4 volts you're doing damage to the battery.

Most likely not.

 

What is the weight difference?

 

The deeper you discharge a battery the sooner you'll have to replace it. Rather than looking at a battery tester you should look at a voltmeter and when you drop below 12.4 volts you're doing damage to the battery.

Weight difference 58# vs. 38#

Also I heard that you can deep discharge a AGM battery with less damage then a regular deep cell.

20# isn't enough of a weight difference to risk what will likely be a situation where you run out of power and wear the battery down faster. AND you'll likely pay way more for that AGM.

Well, for the "most" days you come in and still have 60% - 70% charge left, the smaller battery would work just fine.  My question would be, what about those other days when you use more than your normal 30% - 40%.

 

As for running an AGM down further than a flooded cell battery, no, you should not.  You should never run any battery down below 20% charge,  Doing so shortens the life.  In the ideal world, you don't want to run one down below 50%.   With that said though, a proper maintained AGM is stll going to give you several hundred cycles, even run all the way down to 20%.  Meaning it will probably die from non use before you get all the goody out of it's life cycles because you are still talking several years.   

 

I agree with you on dropping the weight.  When I'm in south Texas visiting my son, we go a lot of times just for a couple of hours in the morning and evening with the jon boat, thrown in the back of his truck.  I bought a small AGM just for those times because when you slinging a 60 - 70 pound flooded cell around, it gets old real quick.